Rotary die blade member bending method, and rotary die blade member binding device

ABSTRACT

Method and apparatus for making a rotary die blade from a straight blade blank to be conformable to the contour of the rotary die block include inserting a blade blank between a first press face of a first presser and a second press face of a second presser; and compressing the blade blank by urging either of the first press face or the second press face to the other, thereby elongating the blade blank along its length; wherein the compressive force is differentiated such that a stronger compressive force is applied to the peripheral portion of the blade blank than the inner portion thereof.

TECHNICAL FIELD

The present invention relates to method and apparatus for making arotary die blade from a straight blade blank, and more particularly,method and apparatus for making a rotary die blade from a straight bladeblank conformable to the contour of the die block.

BACKGROUND ART

A rotary die equipped with a blade is used for perforating a work, suchas paper, to facilitate separation, or for punching or stamping. FIGS.14 and 15 show a rotary die block 100 and a rotary anvil 200 used inassociation with the rotary die block 100. The die blade 1 has a cuttingedge 12 which is curved along the contour of the die block, andprojected beyond its periphery so as to penetrate a work (W) such aspaper or metal sheet.

By referring to FIGS. 14 and 15, the conventional rotary die unit willbe described:

A work (W) such as paper or metal sheet is passed between the rotary die100 equipped with a die blade 1 and the rotary anvil 200 in thedirection (F) indicated by the arrow. While passing therebetween, thework (W) is subjected to perforating or slitting or stamping operationsas desired by the blade 1. The rotary anvil 200 has two kinds; onehaving a hard surface as of iron, and the other having a soft surfacemade as of rubber, depending upon the nature of the work (W).

The blade 1 fixed to the rotary die block 100 has two kinds; one isobtained by curving a straight strip shown in FIG. 16, and shaping it onthe user's side as shown in FIG. 17, and the other is obtained byprocuring a previously curved blade commercially available. In thelatter case, it will be very handy if the obtained blade has a curvatureas desired, and in the former case, the blade can be curved on theuser's side to a desired curvature, where, as shown in FIG. 17, threerollers 301, 302 and 303 are employed with one being inside and theother two outside. Each of the rollers 302 and 303 is provided with agroove on its rim so as to support the edge 12 in a non-contact manner.This method is disclosed in Japanese Patent Publication No. 46(1971)-18352.

The problem arises from the latter case shown in FIG. 19, in the form ofthe betrayal of the expectations of handiness and readiness because ofthe difficulty in selecting a curvature agreeable to the desired value.The problem of the former case shown in FIG. 17 is that parts (A) arelikely to remain unprocessed because of the structural limitationinherent in the illustrated type of machine. These unprocessed parts (A)must be removed by an extra process, thereby increasing the productioncost.

Therefore, an object of the present invention is to provide a method andapparatus for obtaining rotary die blades conformable to the contour ofthe die block throughou its full length.

Another object of the present invention is to provide a method andapparatus for variously shaping the edge of the die blade as the userdesires.

A further object of the present invention is to provide a method andapparatus for ensuring the conformity of the die blade to the contour ofthe rotary die block without requiring a special skill.

A still further object of the present invention is to provide a methodand apparatus for ensuring the conformity of the die blade to thecontour of the rotary die block under a computer control.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided amethod for making a rotary die blade from a straight blade blank,includes inserting a blade blank between two pressers, that is, a firstpresser having a first press face, and a second presser having a secondpress face, respectively; and compressing the blade blank by urgingeither of the first press face or the second press face to the other,thereby elongating the blade blank along its length under compression,wherein a stronger compressive force is applied to the peripheralportion of the blade blank than to the inner portion thereof.

In an alternative embodiment the blade blank is provided with aplurality of slits produced at intervals, wherein the distance betweenthe bottom of each slit and the outside rim of the blade blank is notlarger than one half of the full width of the blade blank.

According to another aspect of the present invention, there is providedan apparatus for making a rotary die blade from a straight blade blank,includes a first presser having a first press face and a second presserhaving a second press face; a first carrier carrying the first presser;a second carrier carrying the second presser; and a housing foraccommodating the pressers and the carriers of the pressers; whereineither of the first carrier or the second is movable to and from theother carrier, thereby bringing the press faces into contact with eachother so as to compress the blade blank.

In an alternative embodiment, each of the first and second press facesis inclined so as to form an upwardly diverged space between the twopress faces, thereby differentiating the compressive force between alower section and an upper section of the diverged space when the twopress faces are brought into contact with each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic perspective view showing an apparatus embodyingthe present invention;

FIG. 2 is a diagrammatic side view to show the internal structure of theapparatus shown in FIG. 1;

FIG. 3 is an explanatory view showing the positional relationshipbetween a blade blank and the presser;

FIG. 4A is a diagrammatic sectional view taken along IV—IV line in FIG.3 where a blade blank is inserted between the two pressers, and FIG. 4Bis a diagrammatic sectional view taken along IV—IV in FIG. 3 where thetwo pressers are brought into contact with each other, with the bladeblank therebetween;

FIG. 5 is an explanatory view illustrating the process of applyingcompression and elongation to the blade blank;

FIG. 6 is a diagrammatic view showing an advantageous case where apresser adapted for shaping the blade blank has a desired shape;

FIG. 7 a diagrammatic view explaining another advantageous case where apresser has a desired shape;

FIG. 8 is a diagrammatic view showing the shapes of the press faces;

FIG. 9 is a diagrammatic plan view showing a blade blank bent in adirection of thickness;

FIG. 10 is a diagrammatic plan view of another type of blade blank;

FIG. 11 is a diagrammatic plan view of a pre-curved blade blank;

FIG. 12 is a diagrammatic perspective view of a blade blank in theprocess of being curved;

FIG. 13 a diagrammatic perspective view of a blade blank which has beencurved;

FIG. 14 is a diagrammatic perspective view illustrating the manner ofoperating the apparatus of the present invention;

FIG. 15 is a diagrammatic side view illustrating the manner of operatingthe apparatus of the present invention;

FIG. 16 is a diagrammatic plan view of a strip-like blade blank;

FIG. 17 is a diagrammatic view exemplifying the conventional method ofcurving a blade blank;

FIG. 18 is a diagrammatic view illustrating the conventional rollersystem of curving a blade blank; and

FIG. 19 is a diagrammatic plan view of a curved blade blank available incommerce.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, an apparatus embodying the present inventionwill be more particularly described by way of example:

The apparatus includes a box 2, a working table 3 thereon, and a pair ofpressers 4, 5 whose heads project through a slit 21 produced in the topsurface of the working table 3. The pressers 4 and 5 include a body 6and an arm portion 7, respectively, each accommodated in the box 2 asshown in FIG. 2. The presser 4 has a press face 4 a, and the presser 5has a press face 5 a mating with the press face 4 a when a blade blankis inserted therebetween.

The body 6 includes a column portion 9, and is moved to the left andright in FIG. 2 by means of handles 14A and 14B, thereby adjusting anangle at which the press face 4 a is faced to the press face 5 a of thepresser 5. The column portion 9 is provided with known connectors 10(their details are omitted for simplicity) each having a threaded bore11, the connectors 10 being rotative around their axis.

Each of the handles 14A and 14B has a threaded bar 13A and 13B,respectively, engageable with the threads of the bore 11A and 11B, thethreaded bar 13A being passed through a side wall 12A of the box 2.Likely, the threaded bar 13B is passed through a side wall 12B. Thethreaded bars 13A and 13B advance and retreat in accordance with aclockwise or counter-clockwise rotation of the handles 14A and 14B,thereby adjusting an angle of decline of the press face 4 a of thepresser 4 against the press face 5 a of the presser 5.

The arm portion 7 of the presser 5 is rotatively supported by a shaft15, and includes an eccentric cam unit 8 that consists of a rotary cam18 fixed to a rotary shaft 17 of an electric motor 16. The rotary cam 18is housed in a hole 19 with a free space. When the rotary cam 18 isdriven by the motor 16, the cam 18 is caused to slide in the arrowdirection on and along the periphery of the hole 19, so that the armportion 7 is caused to rotate around the shaft 15. As a result of therotary movement of the arm portion 7, the presser 5 is caused toapproach and separate from the presser 4. The motor 16 is operated by aswitch 16 (FIG. 2).

As shown in FIG. 3, a blade blank (pre-processed at this stage) 1 has arim having an edge 12, and a flat side having slits 22 at intervalsalong the rim. Each slit 22 has a bottom 23, spaced from the edge 12 byH2, in contrast to the full width H1. The width H2 is not larger thanone half of the width H1.

As shown in FIGS. 4A and 4B, the blade blank is inserted between thepressers 4 and 5; more exactly, between the two press faces 4 a and 5 a.An enlarged view is shown in FIG. 8. FIG. 3 indicates the relationshipbetween the press face 4 a and the blade blank, especially the slit 22.Each of the press faces 4 a and 5 a can have various surfaces, such asflat or convex, depending upon the hardness of the blade blank. Asclearly shown in FIG. 4B, the space between the press faces 4 a and 5 adiverge upward, because the space is defined by the slant press faces 4a and 5 a. The outside wall 13 of the blade blank is initially straightas shown in chain line 13, and is scraped under the pressure provided bythe press faces 4 a and 5 a as shown in solid line 13. In this way thetop end of the blade blank is sharpened as a whole.

In the illustrated example the press face 4 a is inclined at θ1 incontrast to the straight sidewall of the blade blank, and the press face5 a is equally inclined at θ2, wherein θ1 and θ2 are the same angle butthey can be different when desired.

Now, the manner of curving a blade blank by the illustrated apparatus:

Referring to FIGS. 2 and 4A, after the pressers 4 and 5 becomeseparated, the blade blank is vertically suspended between the pressers4 and 5 with its edge 12 downward. At this stage the motor 16 isstarted. The presser 5 is rotated in the arrow direction F in FIG. 4.The strip kept into contact with the press face 4 a of the presser 4, sothat the blade blank extends in length under the compression. Thereduction in thickness under the compression is indicated by (d) in FIG.4B.

As described above, the press faces 4 a and 5 a diverge upward withrespect to the outside wall of the blade blank, so that the compressiveforce focuses upon a point near the edge 12. As the compressionincreases, a metal flesh near the edge 12 is elongated longer than ametal flesh portion away from the edge 12. The diverging of the pressfaces 4 a and 5 a is effective to accomplish the sharp edge 12 becauseof the focused compressive force to around the edge 12.

Then, the process advances to the step where the edge 12 is curved so asto achieve the curved blade blank as shown in FIG. 5. The process isconducted by passing the blade blank consecutively in the direction (a)between the pressers 4 and 5 by N1, N2, N3 . . . Nn. The compression isapplied to each part N, N2, N3 . . . Nn. In this way the whole length ora predetermined range of the blade blank is curved as a whole. It is notessential to apply the compression continuously to every part N1, N2, N3. . . Nn, but it is possible to provide non-compression zones by placingspaces between adjacent parts.

FIG. 9 diagrammatically shows one example of a possible shape of theblade blank, characterized by a valley portion P1 and hill portions P2and P3 with the valley portion P1 interposed therebetween.

FIGS. 11 to 13 indicate the process of obtaining a special type of blade1 mounted on a rotary die block 100 illustrated in FIG. 14. FIG. 11shows a framework-like blade 1 obtained by curving the blade blank. Asevident from FIG. 11, the edge 12 is placed on the same plane throughoutits length.

FIG. 12 shows a modified blade in which the blade 1 is partly raised bymeans of the pressers 4 and 5 in the manner shown in FIG. 5. The exampleof FIG. 12 has its one side alone raised or curved upward, and theexample of FIG. 13 has its both sides raised.

The curving can be started at any point along the blade blank, andcontinued in any range, at its full length or at a part of it. In thiscase, the same pair of pressers 4 and 5 having the press faces 4 a and 5a as shown in FIG. 8 can be employed.

Another modification can be also possible by a process shown in FIG. 6,where the pressers 4 and 5 have sharpened tops whose ends provide pressfaces 4 a and 5 a. FIG. 7 shows a further modification where thepressers 4 and 5 have flat sides 4 b, 5 b. The blade blank rests on theflat side 4 b as shown in FIG. 7. Then it is possible to curve by thepaired pressers 4 and 5 the blade blank at a position where it has beenbent rectangularly. In this case, the pressers 4 and 5 are also carriedon the body 6 and arm portion 7 shown in FIG. 2.

An example shown in FIG. 10 is unique in having a wavy edge 12. Thismodified edge 12 is used as a rotary die blade for perforating amaterial such as paper and cloth to facilitate separation.

In the example shown in FIG. 2, the presser 5 is moved in accordancewith the rotation of the shaft 15, and drawn to the other presser 4 orseparated therefrom, as the case may be. It is possible to move thepresser 5 toward the presser 4 in accordance with the straight movementof the arm 7.

According to the present invention, a straight blade blank can be curvedover its full length like an arch or over a predetermined length. Whenthe blade is given a wavy edge as shown in FIG. 10, it can be used as arotary die blade to perforate a work such as paper and a metal sheet.The operation of the apparatus of the present invention can becomputerized, thereby allowing an unskilled operator to operate theapparatus.

1. A method for making a rotary die blade from a straight blade blank,comprising the steps of: inserting a blade blank between a first pressface of a first presser and a second press face of a second presser; andcompressing the blade blank by separating either of the first press faceor the second press face from the other and urging one of them to theother, thereby elongating the blade blank along its length; wherein thecompressive force is differentiated at a position where the blade blankis compressed, such that a stronger compressive force is applied to theperipheral portion of the blade blank than the inner portion thereof ina widthwise direction of the blade blank.
 2. The method of claim 1,further comprising the step of bending the blade blank into a desiredshape in a thickness direction before the compressing step.
 3. Themethod of claim 1, wherein the blade blank is advanced along its lengthstep by step, with the compression being applied thereto at each step.4. The method of claim 1, wherein each of the pressers is provided witha narrow press face conformable to the width of the blade blank.
 5. Themethod of claim 4, wherein the pressers have press faces divergingupward with respect to the blade blank.
 6. The method of claim 1,wherein the blade blank has an outside rim and is provided with aplurality of slits each of which is produced at intervals and has abottom, wherein the distance between the bottom of each slit and theoutside rim of the blade blank is not larger than one half of the fullwidth.
 7. An apparatus for making a rotary die blade from a straightblade blank which has an edge at one end in a widthwise direction,comprising: a pair of pressers comprising a first and a second presserhaving narrow press faces arranged with the blade blank placedtherebetween so as to be able to separate them from each other andapproach them to one another; and a means for separating the pressersfrom each other and urging the pressers to one another so as to compressand elongate the blade blank, wherein the compressive force isdifferentiated at a position where the blade blank is compressed, suchthat a stronger compressive force is applied to the peripheral portionof the blade blank than the inner portion thereof in a widthwisedirection of the blade blank.
 8. The apparatus of claim 7, furthercomprising means for enabling the blade blank to advance along itslength step by step, with the compression being applied thereto at eachstep.
 9. The apparatus of claim 7, wherein each of the first and secondpress faces is inclined so as to form an upwardly diverged space betweenthe two press faces, thereby differentiating the compressive forcebetween a lower section and an upper section of the diverged space whenthe two press faces are brought into contact with each other.
 10. Theapparatus of claim 7, wherein one of the pressers is fixed, and theother is movable with respect to the fixed presser.
 11. The apparatus ofclaim 7, further comprising a pair of handles each connected to a firstcarrier through threads so as to enable the first carrier to movehorizontally to and from the second presser, each of the handles havinga head projecting outside a housing.
 12. The apparatus of claim 7,wherein one of the paired pressers is connected to one end of an armswingable around a support axis and an eccentric cam mechanism forswinging this arm around the support axis is connected to the other endof the arm.
 13. The apparatus of claim 7, wherein one of the pairedpressers is connected to an inclining mechanism which makes anadjustment to change an inclination angle of its press face.